To provide direct evidence that targeting class II HDACs can enhance the antitumor activity of MGCD0103 in pancreatic cancer cells, shRNA knockdown stable clones for HDAC4 (designated HDAC4-shRNA cells), HDAC6 (designated HDAC6-shRNA cells), and a negative control (designated NTC-shRNA cells) were generated in PANC-1 cells (Figure 3G). Here, HDAC4 is linked to pancreatic neoplasm.